Interpretive Summary: Because of sampling difficulties, fine-scale behavior of Rocky Mountain elk (Cervus elaphus) and beef cattle (Bos taurus) are not well understood. We tested the hypothesis elk and cattle exhibit different innate diurnal behavioral strategies and that differences could be quantified using GIS and GPS tracking collar technologies. We found similarities in diurnal activity budgets between species but elk exhibited a pattern of long periods at rest broken by very short periods of high velocity movement, perhaps a predator avoidance strategy, which cattle did not exhibit. Because these species often use the same rangelands, behavior differences we found are very important to agricultural producers and natural resource managers concerned with potential complementary and/or competitive relationships between elk and beef cattle

Technical Abstract:
Rocky Mountain elk (Cervus elaphus) and beef cattle (Bos taurus) exist in a complex social environment that is marked by diurnal activities such as periods of foraging, ruminating, resting, and sheltering. Elk unlike cattle, must be continually alert to potential predators. We hypothesize that elk and cattle exhibit different innate diurnal behavioral strategies that could be quantified using GIS and GPS technologies. Our study described and compared the diurnal activities of elk and Cattle while grazing rangelands in northeastern Oregon. The study site consisted of two pastures (33.7 and 21.8 ha) that were split on the Starkey Experimental Forest and Range 34 km west of La Grande, Oregon (118.505225°W 45.242308°N). These pastures are composed of four plant communities: dry meadows, Douglas fir/oceanspray, Douglas fir elk sedge, and grand fir/pinegrass. Two herds of five elk and two herds of five cows each were observed in a randomized cross-over experimental design where each animal species occupied ½ of each study pasture for six days then was switched to the other half. This study was replicated twice (June 2007 and September 2007). Animals were directly observed during daylight hours and continuously monitored with GPS collars recording positional fixes each second. Animal paths were analyzed in a GIS environment. Diurnal spatial activity was measured as: distance traveled per day, time spent foraging, time spent stationary, travel velocities, and foraging dynamics. Foraging dynamics were extracted as velocity through various plant communities, time spent grazing in various communities, turning frequency at community boundaries, and path sinuosity.